If Johnny Pemberton had followed family tradition, he’d be cutting up patients on an operating table instead of cutting up audiences in comedy clubs and on the small screen.

The Rochester native, who appears in the new ABC sitcom “Family Tools,” comes from a long line of Mayo Clinic surgeons, starting with great-grandfather John DeJarnette Pemberton, who worked alongside the hospital’s founding brothers.

But the Lourdes High School graduate went another direction.

“I thought about a career in science. I still do,” Pemberton said by phone from Madison, Wis., where he performed at a comedy club the same night of the “Tools” premiere. “I didn’t realize comedy was something you could do as a career. I just kind of fell into it.”

“Tools” revolves around perennial loser Jack Shea (Kyle Bornheimer), who, after being kicked out of the seminary, is called back to his hometown by his aunt (Leah Remini) to help his ailing father (J.K. Simmons) run his repair business. Needless to say, the partnership is a wreck. At one point, Jack shoots himself in the foot. Literally.

Pemberton doesn’t have a lot of scenes in the early episodes, but he makes the best of what he’s given. He plays Jack’s cousin Mason, a bizarre kid who finds it perfectly natural to light firecrackers in the basement and to start a rock band without an iota of musical talent.

Family Tools

When: 7:30 p.m. Wednesdays.

Where: KSTP, Ch. 5.

Perhaps the most remarkable thing about the performance is that the character is 15. Pemberton is 31.

His boyish look is the result of ulcerative colitis, a rare and sometimes fatal inflammatory bowel disease that can stunt one’s growth.

“I don’t feel like there’s a realm of my existence that wasn’t affected by that,” said Pemberton, who went into remission around age 20. “It was incredibly negative and horrible to deal with, but learning to deal with it made me stronger.”

After graduating from Florida State University, he mustered the courage to move to Los Angeles, where he snagged a behind-the-scenes job at Fox Broadcasting. At night, he would hit the clubs to hone his stand-up act.

“I thought he had lost his mind,” said his father, John Pemberton, a Mayo surgeon whose specialties include, of all things, ulcerative colitis.

Father and mother (Elise) watched from afar as their son’s career slowly developed with bit parts in the films “In the Loop,” “21 Jump Street” and “This Is 40.” He even tested out dangerous vehicles on the short-lived MTV series “Megadrive.”

“Tools” is a whole different operation.

“It’s been fun, but difficult,” he said. “I come from an improv background, but there’s not a lot of flexibility in terms of performing on a sitcom. TV is like a factory, where you’re just churning out the work. J.K. [Simmons] taught me early on that if you like a take, they’ll use the one you didn’t like.”

Pemberton is also pragmatic about the show’s chances for success. The network kept it on the shelf for almost a year and cut down its initial order of 13 episodes to 10. The pilot episode drew fewer than 6 million viewers, a disappointing number considering it’s the lead-in to the megahit “Modern Family.”

“A lot of things live or die by how much they’re promoted, and I haven’t seen a lot of billboards for us. Whatever,” Pemberton said. “TV is ruthless. It doesn’t care about anybody’s feelings. You just have to enjoy making it and then, once you’re done, it’s like it never happened.”

His parents will continue to track his career and applaud his efforts, but Dad does admit that part of him hoped that one of his children would follow in his footsteps. “It never worked on any of them,” he said. “We’re zero for four.”